Accidents caused by errors and inattention have long plagued industrial society. Many of these accidents are the result of operator fatigue or from health related issues affecting alertness, such as drug side-effects. An effective and practical tool to screen individuals for temporary impairment, before starting work, is vital and urgent. Bowles-Langley Technology, Inc. has developed a computer test to quickly assess an individual's level of fatigue and alertness. The test measures a number of brain performance factors using a computer game- like graphic. Subjects respond by pressing either a YES or a NO button on the tester. Subjects are measured in comparison to their own baseline. This system will screen workers on a daily or periodic basis. Users will include truck drivers, bus drivers, airline pilots, rail workers, air baggage inspectors and maritime workers. Phase I trials showed the software to be sensitive to mild fatigue. The current objective is to increase software stability and to test validity using statistical analysis of experimental results. Tests will be conducted with human subjects at Bowles-Langley Technology's facilities and at the Circadian Technology Sleep Lab. An additional trial will be conducted in a workplace setting with hospital emergency workers. Data will be analyzed using modern Item Response Theory and other statistical methods. The trials will be conducted using the PC platform, but the intended platform is a patented tester suitable for industrial locations. These testers may be quickly deployed and have wide commercial application. [unreadable] [unreadable]